1. Field of the Invention
The present invention relates to hand manipulated dental implements and particularly to a manually-operated and adjustable dental implant torque wrench which employs a bevel gear and pinion set, each of which is attached to a shaft, the bevel gear being attached through its shaft to a T-handle and the pinion gear is attached to the drive mechanism, said drive mechanism is located in an angled and offset head for accessibility to the patient's rear teeth and is equipped with a screw holding sheath.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
A dental implant, popularly known as a tooth implant, is an artificial root and tooth which are used to replace a missing tooth (or teeth). Dental implants are placed in the jaw to provide support for a dental restoration, fixed bridge or removable partial denture. Dental implants provide good chewing function and also improve the patient's cosmetic appearance thereby allowing the patient to smile, speak, and interact with others with greater confidence. The dental implants as well as other oral surgery involve dental screws which must be placed in line with threaded implanted screw receptacles and screwed into them to specific torque levels.
The mouth can only open so far. The average range of opening is between 40–50 mm. The average movement of the mandible (lower jaw) from side to side (right to left) is 7 mm. The average amount of mandible movement in a forward position is also about 7 mm. It is necessary to provide an instrument that will enable the clinician who is performing dental restorative (placing crowns, bridges or bars onto the implants once the bone has integrated and fused to the implants) procedures to:
bring screws to the mouth without dropping them in the throat area,
to be able to access difficult areas of the back of the mouth
and to be able to torque screws to the manufacturer's specifications.
To date there are no such item as a lock washer that can be placed on a screw that retains a crown or bridge to the dental implant. Every time the cycle of chewing is performed an impact moment is accomplished. Meaning, the teeth come together as if a hammer is hitting the head of a nail. The result is, the threads of the screw and the threads within the implant (the nut in this case) can disengage allowing the screw to back out and loosen. After many cycles of this impact moment occurring the screw can back out and the crown or bridge (teeth supported on the implant(s) become loose. Screws can fracture as a result making their retrieval potentially challenging. They can become wedged inside the implant body.
None of the prior art devices adequately address the problem of bringing the dental screws into the mouth and accurately positioning them for screwing into the implanted threaded socket, especially for the back area of the mouth.
U.S. Pat. No. 5,626,474, issued May 6, 1997 to Kukla, is for a manually operated dental implant torque wrench with an elongated shaft assembly having a first shaft end and a second shaft end. A manually operable control device is connected to the first shaft end of the elongated shaft assembly for rotating the elongated shaft assembly. An angled housing assembly having a passageway extending from a first open end of the housing to a second open end of the housing is provided. The housing has a first portion and a second portion in an angled relationship to the first portion. A drive assembly is provided within the passageway and is operatively connected to the elongated shaft assembly. The drive assembly includes a receptacle end rotatably mounted to the second open end and adapted for attaching a dental tool thereto. An adjustable torque limiting assembly is connected to the elongated shaft assembly for disengaging the elongated shaft assembly from rotation of the drive assembly when rotation of the elongated shaft assembly has reached an adjustable predetermined torque setting.
U.S. Pat. No. 6,162,053, issued Dec. 19, 2000 to Hollander, concerns an analog dental wrench with selectable adjustable torque-shear limits in which, at a given level of torque imparted to a dental work object, force communicated by a compression spring through an interface impart against a ball bearing will cause rotation of a handle and medial hollow cylindrical segment of the wrench off of the bearing to an off-axis position relative to a longitudinal work axis, disabling a wrench head, precluding further application of a torque to the work object, and causing shear of the wrench to occur either to the left or right of the longitudinal axis, and external to the mouth of the patient.
U.S. Pat. No. 5,337,638, issued Aug. 16, 1994 to Coss, illustrates an adjustable torque wrench for procedures requiring the application of precise small torques. The wrench includes a handle pivotally connected to a cam member rigidly attached to a driving head. The handle breaks out of alignment with the extending cam member upon application of an adjustable torque limit. A spring-biased plunger within the handle normally holds a rigid ball within an elliptical indent in the cam member. Application of the torque limit on the handle forces the ball out of the indent and onto an angled surface before a projecting flange of the handle contacts the cam member and limits the further pivot of the handle. The angled surface provides a reaction force to the ball sufficient to maintain the handle in a pivoted position. The handle pivots a noticeably large angle of 30.degree. before the flange contacts the cam member.
U.S. Pat. No. 4,680,994, issued Jul. 21, 1987 to Singleton, provides a speed socket wrench with a reversing ratchet, which substantially reduces the work required to remove nuts or bolts. The wrench includes a bevel gear and mating bevel pinion mounted respectively on a gear shaft and pinion shaft. A drive shaft is provided on the outer end of the pinion shaft. Interlocking cap elements are provided on the outer end of the drive shaft for releasably locking the drive shaft to prevent rotation thereof. In one embodiment, the cap elements include inner and outer caps which cooperate to provide a locking mechanism. In the locked position of the caps, the wrench can be employed as would any conventional wrench. In the unlocked position, a handle on the outer end of the gear shaft is rotatable by hand, resulting in revolving of the drive shaft. The gears of the present wrench turn freely in either direction and gear ratios and sizes can be varied with wrench size. In a further embodiment, a reversing ratchet mechanism is employed to lock the drive shaft.
U.S. Pat. No. 4,991,470, issued Feb. 12, 1991 to Singleton, shows a speed socket wrench with an improved handle which substantially reduces the work required to remove nuts or bolts. The wrench includes a bevel gear and mating bevel pinion mounted respectively on a gear shaft and pinion shaft. A drive shaft is provided on the outer end of the pinion shaft. A reversing ratchet mechanism is employed to lock the drive shaft. The specific construction and arrangement of components provides a socket wrench has been found to substantially reduce the work required to remove nuts or bolts, as compared with conventional wrenches. The present invention provides an improved T-handle for use with a tool having a shaft which rotates about its longitudinal axis. The T-handle is constructed with a generally L-shaped end member, having the shorter leg of the end member extending outwardly at an angle such as about 45 degrees and with the end member being pivotable at its center about the shaft so as to form an angle with the shaft which is complementary to the angle formed by the shorter leg of the end member with the main portion of the end member. In this manner, there is obtained a lever arm that is parallel to the shaft in the operating mode.
U.S. Pat. No. 4,262,561, issued Apr. 21, 1981 to Mize, claims a ratchet and gear drive socket wrench handle. An elongated handle is provided defining a hand grip at one end and an enlarged head at the other end. The enlarged head has a reversible ratchet-type drive assembly supported therefrom including a rotary output shaft disposed transverse to the handle. The handle is tubular intermediate the handle and head ends thereof and rotatably receives a torque input shaft extending therethrough. The torque input shaft and output shaft include meshed gear wheels and the end of the input shaft adjacent the hand grip includes first torque transfer structure. An elongated head is positioned adjacent and disposed transverse to the hand grip in alignment therewith and includes laterally projecting second torque transverse structure releasably coupled with the first torque transverse structure. The elongated head, on the side thereof remote from the head end of the handle, defines an elongated laterally opening groove formed therein and an elongated crank arm has one end pivotally mounted in one end of the groove for swinging of the crank arm between a retracted position within the groove and an extended position projecting endwise outwardly of the aforementioned one end of the groove. The other end of the crank arm includes a right angulated terminal end portion generally paralleling the handle when the crank arm is in both the retracted and extended positions.
U.S. Pat. No. 4,907,476, issued Mar. 13, 1990 to Singleton, describes a speed socket wrench with an improved handle which substantially reduces the work required to remove nuts or bolts. The wrench includes a bevel gear and mating bevel pinion mounted respectively on a gear shaft and pinion shaft. A drive shaft is provided on the outer end of the pinion shaft. A reversing ratchet mechanism is employed to lock the drive shaft. The specific construction and arrangement of components provides a socket wrench which has been found to substantially reduce the work required to remove nuts or bolts, as compared with conventional wrenches. The present invention provides an improved T-handle for use with a tool having a shaft which rotates about its longitudinal axis. The T-handle is constructed with a generally L-shaped end member, having the shorter leg of the end member extending outwardly at an angle such as about 45 degrees and with the end member being pivotable at its center about the shaft so as to form an angle with the shaft which is complementary to the angle formed by the shorter leg of the end member with the main portion of the end member. In this manner, there is obtained a lever arm that is parallel to the shaft in the operating mode.
U.S. Pat. No. 4,620,459, issued Nov. 4, 1986 to Singleton, discloses a speed socket wrench which substantially reduces the work required to remove nuts or bolts. The wrench includes a bevel gear and mating bevel pinion mounted respectively on a gear shaft and pinion shaft. A drive shaft is provided on the outer end of the pinion shaft. Interlocking cap elements are provided on the outer end of the drive shaft for releasably locking the drive shaft to prevent rotation thereof. In one embodiment, the cap elements include inner and outer caps which cooperate to provide a locking mechanism. In the locked position of the caps, the wrench can be employed as would any conventional wrench. In the unlocked position, a handle on the outer end of the gear shaft is rotatable by hand, resulting in revolving of the drive shaft. The gears of the present wrench turn freely in either direction and gear ratios and sizes can be varied with wrench size.
U.S. Pat. No. 2,703,030, issued Mar. 1, 1955 to Marvin, provides a manual gear-operated ratchet wrench that comprises a body having a bevel gear and pinion set, each of which is attached to a shaft. The bevel gear is attached through its shaft to a crank-type handle and the pinion set is attached to the drive mechanism.
U.S. Pat. No. 6,007,336, issued Dec. 28, 1999 to Sapkos, is for a dental prosthesis support device that can be positioned in a dental implant by mating screw threads with the support device being torqued to a predetermined torque, preferably using a torque wrench which can be set using a non-variable, preferably gravity-based, standard.
What is needed is an instrument that can carry a dental screw to a desired location anywhere in a mouth of a patient including in the back of the mouth without dropping it and can effectively turn the dental screw to the required torque level in all locations including the very rear of the mouth to allow greater confidence and ease of treatment when rendering procedures involving dental screws and provide the capability of being able to torque the screw to the desired torque level.